Nigerian health officials are awaiting the results of tests to see if two sick children may be infected with the lethal strain of the bird flu virus.
Samples taken Sunday from the children and their family will determine if they are the first human victims of the disease in Africa.
The children are from the northern state of Kaduna, where officials have confirmed discovery of a "highly pathogenic" version of the H5N1 strain on a chicken farm. It was Africa's first reported case of the lethal strain of bird flu.
That strain has since been confirmed in the Nigerian states of Plateau and Kano, where as many as 20 farms may be affected.
International experts continue to arrive in Nigeria to help with containment efforts, that have included the killing of thousands of chickens across the region.
Some information for this report was provided by AFP and AP.